Quite interested in this myself. I would think your chances would be better if you could at least get them to a pint sized pot and then transplant; otherwise, it could be a bitch keeping them watered (weed plants' roots need to breathe, planting right up on a stream and you wont come up with much).
Otherwise, I would say while they are germ'ing, get the target area prepped now and figure out how you are going to monitor all this. You should know if anyone has been around the plants or not since it sounds like you have to take precautions.